/Engine/Source/Runtime/NavigationSystem/Public/NavigationSystem.h
Calculates a path from PathStart to PathEnd and retrieves its overestimated length and cost.  potentially expensive, so use it with caution
[ENavigationQueryResult::Type](API\Runtime\Engine\AI\Navigation\ENavigationQueryResult__Type) GetPathLengthAndCost ( const FVector & PathStart, const FVector & PathEnd, [FVector::FReal](API\Runtime\Core\Math\TVector\FReal) & PathLength, [FVector::FReal](API\Runtime\Core\Math\TVector\FReal) & PathCost, const [ANavigationData](API\Runtime\NavigationSystem\ANavigationData) * NavData, FSharedConstNavQueryFilter QueryFilter ) const